Pre-hospital heparin is not associated with infarct vessel patency and mortality in ST-segment elevation myocardial infarction patients with out-of-hospital cardiac arrest.

BACKGROUND: Pre-hospital heparin administration has been reported to improve prognosis in patients with out-of-hospital cardiac arrest (OHCA). This beneficial effect may be limited to the subgroup of ST-segment elevation myocardial infarction (STEMI) patients. METHODS: To assess the impact of pre-hospital heparin loading on TIMI (Thrombolysis in Myocardial Infarction) flow grade and mortality in STEMI patients with OHCA, we analyzed data from 2,566 consecutive patients from two hospitals participating in the prospective Feedback Intervention and Treatment Times in ST-segment Elevation Myocardial Infarction (FITT-STEMI) trial. RESULTS: In 394 participants with OHCA, 272 (69%) received heparin from the emergency medical service (EMS). Collapse witnessed by EMS (odds ratio (OR) = 3.53, 95%-confidence interval (CI) = 1.54-8.09; p = 0.003) and pre-hospital ECG recording (OR = 3.32, 95% CI = 1.06-10.35; p = 0.039) were identified as parameters significantly associated with pre-hospital heparin use. In univariate analysis, in-hospital mortality was lower in the group receiving heparin in the pre-hospital setting (26.8% vs. 42.6%, p = 0.002). However, in a regression model, pre-hospital heparin use was no longer a significant predictor of mortality (OR = 0.992; p = 0.981). Patency of the infarct artery prior to coronary revascularization, as measured by TIMI flow grade, was not associated with pre-hospital administration of heparin in OHCA patients (OR = 0.840; p = 0.724). CONCLUSIONS: In STEMI patients with OHCA, pre-hospital use of heparin is neither associated with improved early patency of the infarct artery nor with a better prognosis. Our results do not support the assumption of a positive effect of heparin administration in the pre-hospital treatment phase in STEMI patients with OHCA. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00794001.

Barriers to successful dispatcher-assisted cardiopulmonary resuscitation in out-of-hospital cardiac arrest in Korea.

Introduction: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) improves bystander CPR rates and survival outcomes. This study aimed to identify barriers to successful DA-CPR in patients with out-of-hospital cardiac arrest (OHCA). Methods: This retrospective observational study used data from a nationwide OHCA database from 2017 to 2021. Adult emergency medical services (EMS)-treated patients with OHCA with a presumed cardiac etiology were enrolled. The main exposure variable was compliance with DA-CPR. The primary outcome was good neurological recovery at hospital discharge. Multivariable logistic regression analysis was conducted to identify the major factors associated with unsuccessful DA-CPR with and without multiple imputations. Causal mediation analysis was conducted using witnessed status as a mediator. Results: In the final analysis, 49,165 patients with OHCA were included. A total of 36,865 (75.0%) patients successfully underwent DA-CPR. A higher proportion of good neurological recovery was observed in the successful DA-CPR group than in the non-successful DA-CPR group (P < 0.001). The following factors were identified as risk factors for unsuccessful DA-CPR: age > 65 years, male sex, OHCA occurring in a non-metropolitan area or private place, unwitnessed status, whether the bystander was a non-family member or non-cohabitant, female sex or had not received CPR training, and primary call dispatchers not receiving any first-aid training. Additional analyses after multiple imputations showed similar results. Mediation effect was significant for most risk factors for unsuccessful DA-CPR. Conclusions: Bystander characteristics (non-family member or non-cohabitant, female, and uneducated status for CPR) and primary call dispatchers not receiving first-aid training were identified as risk factors for unsuccessful DA-CPR.

Views and perceptions of advanced life support practitioners on initiating, withholding and terminating resuscitation in out-of-hospital cardiac arrest in the Emergency Medical Services of South Africa.

Introduction: This study aimed to explore the views and perceptions of Advanced Life Support (ALS) practitioners in two South African provinces on initiating, withholding, and terminating resuscitation in OHCA. Methodology: Semi-structured one-on-one interviews were conducted with operational ALS practitioners working within the prehospital setting in the Western Cape and Free State provinces. Recorded interviews were transcribed and subjected to inductive-dominant, manifest content analysis. After familiarisation with the data, meaning units were condensed, codes were applied and collated into categories that were then assessed, reviewed, and refined repeatedly. Results: A total of 18 ALS providers were interviewed. Five main categories were developed from the data analysis: 1) assessment of prognosis, 2) internal factors affecting decision-making, 3) external factors affecting decision-making, 4) system challenges, and 5) ideas for improvement. Factors influencing the assessment of prognosis were history, clinical presentation, and response to resuscitation. Internal factors affecting decision-making were driven by emotion and contemplation. External factors affecting decision-making included family, safety, and disposition. System challenges relating to bystander response and resources were identified. Ideas for improvement in training and support were brought forward. Conclusion: Many factors influence OHCA decision-making in the Western Cape and Free State provinces, and numerous system challenges have been identified. The findings of this study can be used as a frame of reference for prehospital emergency care personnel and contribute to the development of context-specific guidelines.

Dispatcher nurses' experiences of handling drones equipped with automated external defibrillators in suspected out-of-hospital cardiac arrest - a qualitative study.

BACKGROUND: Reducing the time to treatment by means of cardiopulmonary resuscitation (CPR) and defibrillation is essential to increasing survival after cardiac arrest. A novel method of dispatching drones for delivery of automated external defibrillators (AEDs) to the site of a suspected out-of-hospital cardiac arrest (OHCA) has been shown to be feasible, with the potential to shorten response times compared with the emergency medical services. However, little is known of dispatchers' experiences of using this novel methodology. METHODS: A qualitative semi-structured interview study with a phenomenological approach was used. Ten registered nurses employed at an emergency medical dispatch centre in Gothenburg, Sweden, were interviewed and the data was analysed by qualitative content analysis. The purpose was to explore dispatcher nurses' experiences of deliveries of AEDs by drones in cases of suspected OHCA. RESULTS: Three categories were formed. Nurses expressed varying compliance to the telephone-assisted protocol for dispatch of AED-equipped drones. They experienced uncertainty as to how long would be an acceptable interruption from the CPR protocol in order to retrieve a drone-delivered AED. The majority experienced that collegial support was important. Technical support, routines and training need to be improved to further optimise action in cases of drone-delivered AEDs handled by dispatcher nurses. CONCLUSIONS: Although telephone-assisted routines for drone dispatch in cases of OHCA were available, their use was rare. Registered nurses showed variable degrees of understanding of how to comply with these protocols. Collegial and technical support was considered important, alongside routines and training, which need to be improved to further support bystander use of drone-delivered AEDs. As the possibilities of using drones to deliver AEDs in cases of OHCA are explored more extensively globally, there is a good possibility that this study could be of benefit to other nations implementing similar methods. We present concrete aspects that are important to take into consideration when implementing this kind of methodology at dispatch centres.

EPOS-OHCA: Early Predictors of Outcome and Survival after non-traumatic Out-of-Hospital Cardiac Arrest.

Background: Post-cardiac arrest syndrome (PCAS) after out-of-hospital cardiac arrest (OHCA) poses significant challenges due to its complex pathomechanisms involving inflammation, ischemia, and reperfusion injury. The identification of early available prognostic indicators is essential for optimizing therapeutic decisions and improving patient outcomes. Methods: In this retrospective single-center study, we analyzed real-world data from 463 OHCA patients with either prehospital or in-hospital return of spontaneous circulation (ROSC), treated at the Cardiac Arrest Center of the University Hospital of Marburg (MCAC) from January 2018 to December 2022. We evaluated demographic, prehospital, and clinical variables, including initial rhythms, resuscitation details, and early laboratory results. Statistical analyses included logistic regression to identify predictors of survival and neurological outcomes. Results: Overall, 46.9% (n = 217) of patients survived to discharge, with 70.1% (n = 152) achieving favorable neurological status (CPC 1 or 2). Age, initial shockable rhythm, resuscitation time to return of spontaneous circulation (ROSC), and early laboratory parameters like lactate, C-reactive protein, and glomerular filtration rate were identified as independent and combined Early Predictors of Outcome and Survival (EPOS), with high significant predictive value for survival (AUC 0.86 [95% CI 0.82-0.89]) and favorable neurological outcome (AUC 0.84 [95% CI 0.80-0.88]). Conclusion: Integration of EPOS into clinical procedures may significantly improve clinical decision making and thus patient prognosis in the early time-crucial period after OHCA. However, further validation in other patient cohorts is needed.

Validating quantitative pupillometry thresholds for neuroprognostication after out-of-hospital cardiac arrest. A predefined substudy of the Blood Pressure and Oxygenations Targets After Cardiac Arrest (BOX)-trial.

PURPOSE: Out-of-hospital cardiac arrest (OHCA) survivors face significant risks of complications and death from hypoxic-ischemic brain injury leading to withdrawal of life-sustaining treatment (WLST). Accurate multimodal neuroprognostication, including automated pupillometry, is essential to avoid inappropriate WLST. However, inconsistent study results hinder standardized threshold recommendations. We aimed to validate proposed pupillometry thresholds with no false predictions of unfavorable outcomes in comatose OHCA survivors. METHODS: In the multi-center BOX-trial, quantitative measurements of automated pupillometry (quantitatively assessed pupillary light reflex [qPLR] and Neurological Pupil index [NPi]) were obtained at admission (0 h) and after 24, 48, and 72 h in comatose patients resuscitated from OHCA. We aimed to validate qPLR < 4% and NPi ≤ 2, predicting unfavorable neurological conditions defined as Cerebral Performance Category 3-5 at follow-up. Combined with 48-h neuron-specific enolase (NSE) > 60 µg/L, pupillometry was evaluated for multimodal neuroprognostication in comatose patients with Glasgow Motor Score (M) ≤ 3 at ≥ 72 h. RESULTS: From March 2017 to December 2021, we consecutively enrolled 710 OHCA survivors (mean age: 63 ± 14 years; 82% males), and 266 (37%) patients had unfavorable neurological outcomes. An NPi ≤ 2 predicted outcome with 0% false-positive rate (FPR) at all time points (0-72 h), and qPLR < 4% at 24-72 h. In patients with M ≤ 3 at ≥ 72 h, pupillometry thresholds significantly increased the sensitivity of NSE, from 42% (35-51%) to 55% (47-63%) for qPLR and 50% (42-58%) for NPi, maintaining 0% (0-0%) FPR. CONCLUSION: Quantitative pupillometry thresholds predict unfavorable neurological outcomes in comatose OHCA survivors and increase the sensitivity of NSE in a multimodal approach at ≥ 72 h.

Risk assessment of electric shock to the general public without Personal Protective Equipment during defibrillation shock delivery: A simulation study.

Aim: This study aimed to elucidate the risk of electric shock when the general public, not wearing Personal Protective Equipment (PPE), is in contact with a patient, and a defibrillation shock is inadvertently delivered. Methods: A simulation study was conducted simulating the following scenarios. 1) Both the rescuer and the patient were isolated from the ground, with the rescuer making single-point contact with the patient. 2) Both the rescuer and the patient were in contact with the common ground, and the rescuer made single-point contact with the patient. 3) The rescuer made contact at two different points to the patient. A mannequin with a towel saturated with 3% saline solution placed on the chest was used. Defibrillation shocks were delivered using a defibrillator three times at each of three energies: 150 J, 200 J, and 360 J. The voltage across the simulated rescuer was measured with an oscilloscope. Results: In Scenario 1, all measurements were below the detection limit. In Scenario 2, the voltage and current across the rescuer increased with higher defibrillation shock energy, averaging 156.8 V and 156.8 mA at 360 J. In Scenario 3, voltage peaked at 326.0 V and current at 326.0 mA at 360 J. Conclusion: In a simulated setting of defibrillation, over 300 mA of current could pass through the rescuer without PPE when having two contact points between the manikin and the rescuer. However, due to the brief duration and low energy, immediate danger to the rescuer is considered low.

Gender Differences in Defibrillator Practices in Out-of-Hospital Cardiac Arrest.

OBJECTIVES: Disparities remain in survival after out-of-hospital cardiac arrest (OHCA) for women compared to men. Our objective was to evaluate differences in automated external defibrillator (AED) use before Emergency Medical Services (EMS) arrival and time from arrival to initial EMS defibrillation by EMS-assessed gender (women or men). METHODS: This was a secondary analysis of adult non-traumatic, EMS-treated OHCA cases in the Portland Cardiac Arrest Epidemiologic Registry from 2018 to 2021. Emergency Medical Services-witnessed cardiac arrests were excluded and the primary outcomes were pre-EMS AED application and the time from EMS arrival to first defibrillation among patients in a shockable rhythm at first rhythm assessment without pre-EMS AED application. We examined pre-EMS AED application rates overall and separately for law enforcement, in cases where they were on-scene before EMS without a lay bystander AED applied, and lay responders, in cases where law enforcement had not applied an AED. We used multivariable logistic and linear regressions to adjust for potential confounders, including age, arrest location, witness status, bystander CPR, year, and time from dispatch to EMS arrival. We accounted for clustering by county of arrest using a mixed-effects approach. RESULTS: Of the 3,135 adult, EMS-treated non-traumatic OHCAs that were not witnessed by EMS, 3,049 had all variables for analysis, of which 1,011 (33.2%) were women. The adjusted odds (adjusted odds ratio [95% CI]) for any pre-EMS placement of an AED was significantly higher for men compared to women (1.40 [1.05-1.86]). These odds favoring men remained when examining law enforcement AED application (1.89 [1.16-3.07]), but not lay bystander AED application (1.19 [0.83-1.71]). Among patients still in arrest on EMS arrival, with a shockable initial EMS rhythm, and without pre-EMS AED application, the time from EMS arrival on-scene to initial defibrillation was significantly longer for women compared to men (+0.81 min [0.22-1.41 min]). CONCLUSIONS: Women with OHCA received lower rates of pre-EMS AED application and delays in initial EMS defibrillation compared to men.

Time difference between pad placement in single versus double external defibrillation: A live patient simulation model.

Background: Out-of-hospital cardiac arrest (OHCA) cause significant patient morbidity and mortality. Double sequential external defibrillation (DSED) represents an alternative treatment for OHCA patients, but the use is currently reserved for patients in refractory ventricular fibrillation. However, OHCA patients may achieve return of spontaneous circulation earlier with the use of DSED as initial treatment. This study compares the necessary times needed to establish pad placement in DSED compared to normal pad placement in a live patient simulation model. Methods: This study was an observational cohort study with ambulance personnel and live patient models. The procedure was performed on two patient categories, with BMI 20.9 (patient A) and BMI 32.8 (patient B). Two-member teams established two defibrillators ready for rhythm analysis. Time spent for standard and DSED procedure was registered in the same procedure. All team members performed the procedure on both patient categories. Results: In total, 108 procedures were performed on both patient categories. Mean time to standard pad placement was 24.6 ± 3.3 s for patient A, and 27.4 ± 3.7 s for patients B. Mean time to DSED pad placement was 38.3 ± 7.0 s for patient A, and 41.3 ± 7.4 s for patient B. Mean difference in time needed for DSED versus standard pad placement was 13.7 ± 4.8 s for patient A, and 13.9 ± 4.6 s for patient B. There was no significant difference in time spent between the two patient categories (p = 0.725). Conclusion: The necessary time to establish DSED versus standard defibrillation pad placement was short. This may support clinical studies on DSED as initial treatment for OHCA patients without risk of significant increase in time to first defibrillation.

Sex-specific health-related quality of life in survivors of cardiac arrest.

Survival after out-of-hospital cardiac arrest (OHCA) remains low, although the number of survivors is increasing, and survivors are living longer. With increasing long-term survival, there is a need to understand health-related quality of life (HRQoL) measures. Although there are current recommendations for measuring HRQoL in OHCA survivors, there is significant heterogeneity in assessment timing and the measurement tools used to quantify HRQoL outcomes, making the interpretation and comparison of HRQoL difficult. Identifying groups of survivors of OHCA with poor HRQoL measures could be used for targeted intervention studies. Sex differences in OHCA resuscitation characteristics, post-cardiac arrest treatment, and short-term survival outcomes are well-documented, although variability in study methods and statistical adjustments appear to affect study results and conclusions. It is unclear whether sex differences exist in HRQoL among OHCA survivors and if study methods and statistical adjustment for patient characteristics or arrest circumstances impact the results. In this narrative review article, we provide an overview of the assessment of HRQoL and the main domains of HRQoL. We summarize the literature regarding sex differences in HRQoL in OHCA survivors. Few multivariable-adjusted studies reported HRQoL sex differences and there was significant heterogeneity in study size, timing of assessment, and domains measured and reported. What is reported suggests females have worse HRQoL than males, especially in the domains of physical function and mental health, but results should be interpreted with caution. Lastly, we discuss the challenges of a non-uniform approach to measurement and future directions for assessing and improving HRQoL in OHCA survivors.

Exercise related versus non exercise related out of hospital cardiac arrest - A retrospective single-center study.

Background: Physical activity prevents cardiovascular disease, but it may also trigger acute cardiac events like sudden cardiac death in patients with underlying heart disease. The chance of surviving an out-of-hospital cardiac arrest remains low, despite improving medical treatment and rescue chain. Prior studies signaled increased survival in exercise related out-of-hospital cardiac arrest. Objective: The aim of this study was to evaluate the differences between exercise related out-of-hospital cardiac arrest and out-of-hospital cardiac arrest during daily activity in an urban setting. Methods: Retrospective analysis of all out-of-hospital cardiac arrests from 2014 to 2021 treated at a cardiac arrest center of a tertiary hospital. The primary outcome was survival to discharge. Secondary outcomes included differences in pre-hospital care, in-hospital treatment, hypoxic ischemic encephalopathy, and laboratory parameters. Results: 478 OHCA patients were reviewed of which 432 patients (exercise related 36 (8.4%) vs. daily activity 396 (91.6%)) were included in the analysis. Patients suffering an exercise related arrest were younger (57 vs 65 years, p = 0.002) and mostly male (88.9 vs 74.5%, p = 0.054).The exercise related cohort received bystander cardiopulmonary resuscitation (77.8 vs 53.4%, p = 0.005) to a higher extent and had a shorter no-flow time (1.5 vs 2 min, p = 0.049). Exercise related arrest patients more often presented with a shockable rhythm (80.6 vs 64.1%, p = 0.032).At hospital admission exercise related arrest patients had a higher initial pH (7.24 vs 7.19, p = 0.015). In the exercise related group, a cardiac cause was numerically more frequent compared to the daily activity group (80.6 vs 68.7%, p = 0.09). In both groups myocardial infarction (47.2 vs 43.2%) was the most common cause, but a primary arrhythmic event (33.3 vs 25.5%) was more often documented in exercise related arrest patients. Exercise related arrest was mostly related to endurance training (52.8%) followed by ball sports (19.4%) and occurred directly during exercise in 77.8% of cases. Patients suffering exercise related arrest had higher survival till discharge (66.7 vs 47.7%, p = 0.036). Conclusion: Based on this observational data from a highly selected group of out-of-hospital cardiac arrest patients treated at a cardiac arrest center, patients suffering an exercise related out-of-hospital cardiac arrest, differed in substantial characteristics and in the first line response compared to daily activity out-of-hospital cardiac arrest patients. The better survival to discharge of the exercise related out-of-hospital cardiac arrest group might be driven by these beneficial differences. This study underlines the need for public awareness for the importance of a fast first response and a broad distribution of automated external defibrillators in public sport areas since most of the exercise related out-of-hospital cardiac arrest patients presented with a cardiac cause and an initial shockable rhythm.

Long-Term Impact of the Kumamoto Earthquake on Out-of-Hospital Cardiac Arrest With Cardiac and Non-Cardiac Origins　- An Interrupted Time Series Analysis.

BACKGROUND: Possible etiologies of out-of-hospital cardiac arrest (OHCA), including aortic dissection, ruptured aortic aneurysms, and pulmonary embolism, may be classified as non-cardiac causes. We investigated whether cardiac and non-cardiac OHCAs increased following the Kumamoto earthquake and whether the impact on OHCAs extended to regions far from the epicenter. METHODS AND RESULTS: We prospectively analyzed a nationwide registry of patients who experienced OHCAs between January 2013 and December 2019. Data from cases registered in 7 prefectures, including Kumamoto (Kyushu region; n=82,060), in the All-Japan Utstein Registry were analyzed for OHCAs of cardiac and non-cardiac origin. The numbers of OHCAs before and after the Kumamoto earthquake were compared using an interrupted time series analysis. The incidence of both cardiac (rate ratio [RR] 1.22) and non-cardiac (RR 1.27) OHCAs in Kumamoto Prefecture increased after the earthquake. The difference disappeared when the analysis was limited to patients with non-cardiac OHCAs with a clear cause of cardiac arrest. The number of cardiac and non-cardiac OHCAs did not increase in other prefectures within the Kyushu region. CONCLUSIONS: The Kumamoto earthquake led to an increase in the incidence of cardiac and non-cardiac OHCAs. However, this was attenuated by increasing distance from the epicenter. Except for cardiac causes, cases complicated by earthquake-related events may include non-cardiac OHCAs due to vascular diseases that might be overlooked.

Interventions to optimize dispatcher-assisted CPR instructions: A scoping review.

Aim: To review and summarize existing literature and knowledge gaps regarding interventions that have been tested to optimize dispatcher-assisted CPR (DA-CPR) instruction protocols for out-of-hospital cardiac arrest (OHCA). Methods: This scoping review was undertaken by an International Liaison Committee on Resuscitation (ILCOR) Basic Life Support scoping review team and guided by the ILCOR methodological framework and the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). Studies were eligible for inclusion if they were published in peer-reviewed journals and evaluated interventions used to improve DA-CPR. The search was carried out in MEDLINE, EMBASE, Education Resources Information Center (ERIC), PsycINFO, the Cochrane Library, Evidence Based Medicine (EBM) Reviews, and the Campbell Library from 2000 to December 18, 2023. Results: After full text review, 31 studies were included in the final review. The interventions reviewed were use of video at the scene (n = 9), changes in terminology about compressions (n = 6), implementation of novel DA-CPR protocols (n = 4), advanced dispatcher training (n = 3), centralization of the dispatch center (n = 2), use of metronome or varied metronome rates (n = 2), change in CPR sequence and compression ratio (n = 1), animated audio-visual recording (n = 1), pre-recorded instructions vs. conversational live instructions (n = 1), inclusion of "undress patient" instructions (n = 1), and specific verbal encouragement (n = 1). Studies ranged in methodology from registry studies to randomized clinical trials with the majority being observational studies of simulated EMS calls for OHCA. Outcomes were highly variable but included rates of bystander CPR, confidence & willingness to perform CPR, time to initiation of bystander CPR, bystander CPR quality (including CPR metrics: chest compression depth and rate; chest compression fraction; full chest recoil, ventilation rate, overall CPR competency), rates of automated external defibrillator (AED) use, return of spontaneous circulation (ROSC) and survival. Overall, all interventions seem to be associated with potential improvement in bystander CPR and CPR metrics. Conclusion: There appears to be trends towards improvement on key outcomes however more research is needed. This scoping review highlights the lack of high-quality clinical research on any of the tested interventions to improve DA-CPR. There is insufficient evidence to explore the effectiveness of any of these interventions via systematic review.

Hyperfibrinolysis: potential guidance for decision-making to avoid futile extracorporeal cardiopulmonary resuscitation.

Out-of-hospital cardiac arrest (OHCA) is associated with very poor outcomes. Extracorporeal cardiopulmonary resuscitation (eCPR) for selected patients is a potential therapeutic option for refractory cardiac arrest. However, randomised controlled studies applying eCPR after refractory OHCA have demonstrated conflicting results regarding survival and good functional neurological outcomes. eCPR is an invasive, labour-intensive, and expensive therapeutic approach with associated side-effects. A rapid monitoring device would be valuable in facilitating selection of appropriate patients for this expensive and complex treatment. To this end, rapid diagnosis of hyperfibrinolysis, or premature clot dissolution, diagnosed by viscoelastic testing might represent a feasible option. Hyperfibrinolysis is an evolutionary response to low or no-flow states. Studies in trauma patients demonstrate a high mortality rate in those with established hyperfibrinolysis upon emergency room admission. Similar findings have now been reported for the first time in OHCA patients. Hyperfibrinolysis upon admission diagnosed by rotational thromboelastometry was strongly associated with mortality and poor neurological outcomes in a small cohort of patients treated with extracorporeal membrane oxygenation.

Bystander defibrillation for out-of-hospital cardiac arrest in Ireland.

Aims: To describe and explore predictors of bystander defibrillation in Ireland during the period 2012 to 2020. To examine the relationship between bystander defibrillation and health system developments. Methods: National level Out of Hospital Cardiac Arrest (OHCA) registry data were interrogated, focusing on patients who had defibrillation performed. Bystander defibrillation (as compared to EMS initiated defibrillation) was the key outcome of concern. Logistic regression models were built and refined by fitting predictors, performing stepwise variable selection and by adding pairwise interactions that improved fit. Results: The data included 5,751 cases of OHCA where defibrillation was performed. Increasing year over time (OR 1.17, 95% CI 1.13, 1.21) was associated with increased adjusted odds of bystander defibrillation. Non-cardiac aetiology was associated with reduced adjusted odds of bystander defibrillation (OR 0.30, 95% CI 0.21, 0.42), as were increasing age in years (OR 0.99, 95% CI 0.987, 0.996) and night-time occurrence of OHCA (OR 0.67, 95% CI 0.53, 0.83). Six further variables in the final model (sex, call response interval, incident location (home or other), who witnessed collapse (bystander or not witnessed), urban or rural location, and the COVID period) were involved in significant interactions. Bystander defibrillation was in general less likely in urban settings and at home locations. Whilst women were less likely to receive bystander defibrillation overall, in witnessed OHCAs, occurring outside the home, in urban areas and outside of the COVID-19 period women were more likely, to receive bystander defibrillation. Conclusions: Defibrillation by bystanders has increased incrementally over time in Ireland. Interventions to address sex and age-based disparities, alongside interventions to increase bystander defibrillation at night, in urban settings and at home locations are required.

Identifying Subgroups with Differential Responses to Amiodarone among Cardiac Arrest Patients with a Shockable Rhythm at Hospital Arrival using the Machine Learning Approach.

Background: There are few reports of studies on the differential effects of amiodarone among out-of-hospital cardiac arrest (OHCA) patients with a shockable rhythm at hospital arrival. The present study aimed to investigate the clinical heterogeneity of OHCA patients with a shockable rhythm upon hospital arrival and to identify subgroups with differential responses to amiodarone, using a machine learning approach. Methods: We used the Japanese nationwide OHCA registry of the Japanese Association for Acute Medicine for this study; data from OHCA patients with a shockable rhythm at hospital arrival were included in the analyses. The primary outcome was a favorable neurological outcome at 30 days. We developed a scoring system by the weighting method with logistic likelihood loss to identify patient subgroups showing differential effects of amiodarone from the point of view of the neurological outcome and survival at 30 days. Results: Among the 68,111 cases of OHCA in the registry, the data of 2333 OHCA patients with an initial shockable rhythm at hospital arrival were analyzed. The developed score identified higher age, longer interval between the call to the emergency medical service and hospital arrival, absence of a "witness", no defibrillation prior to hospital arrival, hypothermia at hospital arrival, and pre-hospital epinephrine administration as variables that were significantly associated with a beneficial effect of amiodarone. Based on the results of the developed scoring system, 47% (1107/2333) of the patients were considered to greatly benefit from amiodarone administration, whereas 53% (1226/2333) of patients were considered to not benefit from amiodarone administration. The effect of amiodarone on the neurological outcome at 30 days varied significantly among the subgroups identified by the developed score ( OR interaction : 1.07 [95% confidence interval (CI): 0.99-1.13], p = 0.005). Conclusions: We successfully developed a model that could discriminate between OHCA patients with an initial shockable rhythm at hospital arrival who would benefit or not benefit from the administration of amiodarone in terms of the neurological outcome at 30 days. There was clinical heterogeneity among OHCA patients with a shockable rhythm in terms of their response to amiodarone.

Addressing out-of-hospital cardiac arrest with current technology advances: Breaking the deadlock with a mobile network.

Out-of-hospital cardiac arrest (OHCA) is a global public health problem, with survival rates remaining low at around 10% or less despite widespread cardiopulmonary resuscitation (CPR) training and availability of automated external defibrillators (AEDs). This is partly due to the challenges of knowing when and where a sudden OHCA occurs and where the nearest AED is located. In response, countries around the world have begun to use network technology-based smartphone applications. These applications are activated by emergency medical service dispatchers and alert preregistered volunteer first responders (VFRs) to nearby OHCAs using Global Positioning System localization. Accumulating evidence, although mostly from observational studies, shows their effectiveness in increasing the rate of bystander CPR, defibrillation, and patient survival. Current guidelines recommend the use of these VFR alerting systems, and the results of ongoing randomized trials are awaited for further dissemination. This article also proposed the concept of a life-saving mobile network (LMN), which uses opportunistic network and wireless sensor network technologies to create a dynamic mesh network of potential victims, rescuers, and defibrillators. The LMN works by detecting a fatal arrhythmia with a wearable sensor device, localizing the victim and the nearest AED with nearby smartphones, and notifying VFRs through peer-to-peer communication. While there are challenges and limitations to implementing the LMN in society, this innovative network technology would reduce the tragedy of sudden cardiac death from OHCA.

The time-dependent yield of invasive vs. standard resuscitation strategies: A secondary analysis of the Prague out-of-hospital cardiac arrest study.

BACKGROUND: It is unclear how invasive resuscitative protocols may impact the time-dependent prognosis of out-of-hospital cardiac arrest (OHCA) resuscitations, or the relationship between intra-arrest transport and outcomes. METHODS: We performed a secondary analysis of the Prague OHCA Study, which randomized refractory OHCAs to "invasive" (intra-arrest transport for possible ECPR initiation) vs. "standard" resuscitation strategies (predominantly performed on-scene). Between groups, we compared outcomes of the initial resuscitation and 180- and 30-day favourable neurological outcomes (CPC 1-2), and within categories based on resuscitation duration (collapse-to-ROSC/ECPR interval). We plotted the dynamic probability of favourable outcomes with increasing durations of unsuccessful resuscitation. RESULTS: Among invasive and standard groups, respectively: 34/124 (27%) vs. 58/132 (44%) had sustained ROSC (difference -17%, 95%CI -5.0, -28); 38/124 (31%) vs. 24/132 (18%) had 30-day favourable neurological outcomes (difference 12%; 95%CI 2.0, 23); and 39/124 (31%) vs. 29/132 (22%) had 180-day favourable neurological outcomes (difference 9.5%; 95%CI -1.3, 20). For favourable outcome cases: standard group resuscitation durations were right-skewed within the first 60 min; for the invasive group the distribution was bimodal, extending to 77 min. For invasive- and standard-treated cases, the probability of favourable outcomes among those in refractory arrest at 30 min was 28% and 7.6%, respectively; declining to 0% at 77 and 60 min. CONCLUSION: In comparison to standard resuscitation, invasive strategy cases had fewer achieve sustained ROSC, however improved overall 30-day favourable neurological outcomes. While standard resuscitation yield was limited to < 60 min, invasive protocols offer a second extended window of potential successful resuscitation.

Inflammatory response after prehospital high-dose glucocorticoid to patients resuscitated from out-of-hospital cardiac arrest: A sub-study of the STEROHCA trial.

BACKGROUND: The post-cardiac arrest syndrome (PCAS) after out-of-hospital cardiac arrest (OHCA) is characterized by a series of pathological events, including inflammation. In the randomized "STERoid for OHCA" (STEROHCA) trial, prehospital high-dose glucocorticoid decreased interleukin (IL) 6 and C-reactive protein levels following resuscitated OHCA. The aim of this predefined sub-study was to assess the inflammatory response the first three days of admission. METHODS: The STEROHCA trial enrolled 137 OHCA patients randomized to either a single prehospital injection of methylprednisolone 250 mg or placebo. Inflammatory markers, including pro- and anti-inflammatory cytokines, were analyzed in plasma samples, from 0-, 24-, 48-, and 72 h post-admission. Mixed-model analyses were applied using log-transformed data to assess group differences. RESULTS: The 137 patients included in this sub-study had a median age of 67 years (57 to 74), and the 180-day survival rates were 75% (n = 51/68) and 64% (n = 44/69) in the glucocorticoid and placebo group, respectively. A total of 130 (95%) patients had at least one plasma sample available. The anti-inflammatory cytokine IL-10 was increased at hospital admission in the glucocorticoid group (ratio 2.74 (1.49-5.05), p = 0.006), but the intervention showed the strongest effect after 24 h, decreasing pro-inflammatory levels of IL-6 (ratio 0.06 (0.03-0.10), p < 0.001), IL-8 (ratio 0.53 (0.38-0.75), p < 0.001), macrophage chemokine protein-1 (MCP-1, ratio 0.02 (0.13-0.31), p < 0.001), macrophage inflammatory protein-1-beta (MIP-1b, ratio 0.28 (0.18-0.45), p < 0.001), and tumor necrosis factor-α (TNF-α, ratio 0.6 (0.4-0.8), p = 0.01). CONCLUSION: Administering high-dose glucocorticoid treatment promptly after resuscitation from OHCA influenced the inflammatory response with a reduction in several systemic proinflammatory cytokines after 24 h. TRIAL REGISTRATION: EudraCT number: 2020-000855-11; submitted March 30, 2020. URL: https://www. CLINICALTRIALS: gov; Unique Identifier: NCT04624776.

Microbiological Profiles after Out-of-Hospital Cardiac Arrest: Exploring the Relationship between Infection, Inflammation, and the Potential Effects of Mechanical Circulatory Support.

Background: Cardiogenic shock (CS) following an out-of-hospital cardiac arrest (OHCA) poses significant management challenges, exacerbated by inflammatory responses and infectious complications. This study investigates the microbiological profiles and impacts of mechanical circulatory support (MCS) on inflammation and infection in OHCA patients. Methods: We retrospectively analyzed microbiological data from various specimens of 372 OHCA patients, who were treated at the Cardiac Arrest Center of the University Hospital of Marburg from January 2018 to December 2022. Clinical outcomes were evaluated to investigate the potential impact of MCS on infection and inflammation. Results: Of the study cohort, 115 patients received MCS. The microbiological analysis revealed a higher incidence of positive blood cultures in the MCS group vs. the non-MCS group (39% vs. 27.7%, p = 0.037), with predominantly Gram-positive bacteria. Patients with positive microbiological findings had longer in-hospital stays and prolonged periods of mechanical ventilation. The levels of inflammatory markers such as C-reactive protein (CRP) and procalcitonin (PCT) differed, suggesting a more pronounced inflammatory response in MCS patients, especially in the later ICU stages. Notably, despite the higher infection rate in the MCS group, the survival rates did not significantly differ in the two groups. Conclusions: MCS appears to influence the microbiological and inflammatory landscape in OHCA patients, increasing the susceptibility to certain infections but not affecting the overall mortality. This study underscores the complexity of managing post-resuscitation care and highlights the need for tailored therapeutic strategies to effectively mitigate infectious and inflammatory complications.